Gas burner for blast furnace stoves



A ril 23, 1963 s. P.v KINNEY GAS BURNER FOR BLAST FURNACE STOVES 3 Sheets-Sheet 2 Filed July 15, 1959 JNVENTOR. Selwyne R Kinney ATTORNEYS April 23, 1963 Filed July 15, 1959 S. P- KINNEY GAS BURNER FOR BLAST FURNACE STOVES 3 Sheets-Sheet 3 INVENTOR. Selwyne R Kinney BY M M r ATTORNEYS air ofitake at a level usually above the burner.

United States Patent 3,086,582 GAS BURNER FOR BLAST FURNACE STOVES Selwyne P. Kinney, Pittsburgh, Pa., assignor to S. P. Kinney Engineers, Carnegie, Pa., a corporation of Pennsylvania Filed July 15, 1959, Ser. No. 827,221 7 Claims. (Cl. 158-109) This invention relates to those air heating devices used in heating the air for blast furnaces known in the art as stoves, and the invention is for a gas burner for use on such stoves.

Stoves of the type referred to are tall, cylindrical structures filled with a checkerwork of brick and a vertical combustion chamber usually located inside the stove at one side of the checker brick. The arrangement is such that a burner located at the bottom of the combustion chamber exteriorly of the stove introduces proportioned streams of air and gas into the bottom of the combustion chamber, and this mixture is burned. The hot gases of combustion are deflected at the top of the stove downwardly through the checker brick to heat the brick and flow out through the bottom of the stove to a stack. After a period of operation in this manner, the burner .is disconnected from the stove and the burner opening closed, and air under pressure is introduced into the bottom of the stove to be forced upwardly through the checker brick and down the combustion chamber to an The closure at the bot-tom of the stove where the burner is disconnected is therefore subject to high heat and to the blast pressure.

The burners usually comprise concentric large diameter duets with the inner duct being for gas and the outer one for air. These concentric ducts extend into and are mounted in the burner opening at the base of the stove, so that in a general way, the disconnection of the burner is effected byremoving as a unit a section of these two concentric ducts and replacing this section with a gate of some kind that covers the ends of the ducts in the burner opening to prevent the back flow of heated air into the air duct or gas duct outside the stove.

These stoves are large structures and the closure arrangement is heavy and cumbersome, requiring double hoods or enclosures, or, if provision is not made for the removal of a section of the concentric ducts, expensive valves mustbe used in the air and gas lines.

The present invention has for its object to provide an improved burner in which the inner duct of the burner has an axially movable section, enabling a simple type of disk valve to be used in the outer duct to close the burner when the stove is put on the blast heating cycle.

A further object of the invention is to simplify the cost and size of a burner installation, particularly through the simplifying of the valving required, and better adapt the burner to automatic stove changing procedures.

A further object of my invention is to provide an improved burner organization of simple, unique and compact construction.

These and other objects and advantages are secured by my invention as will be more apparent from the following detailed description of a burner embodying my invention in conjunction with the accompanying drawings, in which:

FIG. 1 is a vertical longitudinal section through the burner and a portion of the stove.

FIG. 2 is a view partly in plan and partly in horizontal section of the burner shown in FIG. 1; and

FIG. 3 is an end elevation of the outer end of the burner, no portion of the stove being shown in this figure.

In the drawings, 2 designates a portion of the shell of a conventional blast furnace stove with a refractory 3,086,582 Patented Apr. 23, 1963 lining 3 and a burner port 3a. The fixed nose portion of the burner is entered into this port and supported by an annular supporting ring 4. The fixed nose of the burner comprises an inner gas duct section 5 supported on radial braces 6 attached to ring 4 and an outer refractory sleeve 7. Butted against a flange 8 on the end of the ring 4 and bolted thereto is a flange 9 on one end of a disk-valve body 10. The valve body 10 may be of any suitable construction having the necessary ability to withstand high temperatures, but I prefer to use at this location a hot blast valve of the type normally used in the duct leading from the stove to the blast furnace, and which per se for-ms no part of the present invention. It is here shown as a well-known type of disk or gate valve having a water-cooled disk 11 with upwardlyextending operating rods 12 in which are pipes for the circulation of water. The valve body has an upwardly.- extending bonnet 13 to receive the valve disk in its raised position. An operating mechanism 13a is above the bonnet. There are water-cooled rings or seats 14 around the interior of the valve body against which the disk 11 seals. If preferred, I may use a valve with only that seat 14 away from the stove water-cooled.

A duct 15 is connected to the other face of the valve body opposite the flange =8, with the internal diameter thereof where it connects to the valve body being the same as the internal diameter of air passage in the burner nose, constitutes an after or outer portion of the air duct of the burner. Rearwardly of the portion that joins the valve, the air duct is expanded in diameter to provide for an air supply pipe 16 that connects into it from one side of the burner, and which leads to a blower 17. The blower 17 has an air inlet connection 18 leading into a vertical air inlet pipe 19 that extends straight upwardly for several feet, at least ten or twelve feet or more with an orifice plate inserted therein near the top at 19a. This gives a straight length of pipe below the orifice plate, enabling an accurate flow of air to be measured across the orifice without utilizing needed ground space. Normally the orifice plate or other air metering means must be close to the fan inlet where air conditions may pulsate.

Inside the enlarged after portion of the air duct there is an elbow 20 with a vertical leg 21 joined to a vertical gas supply pipe 21a and a horizontal leg 22 turned toward the stove. Telescopically fitted over the horizontal leg 22. is an axially movable intermediate gas duct section 23 which may be extended to butt against the end of the fixed duct 5 in the burner nose or retracted to clear the path of travel of the valve disk 11. This movable section 23 has an internal spider 24 which at its center is fixed to a slide rod 25. Rod 25 slidably passes through the center of a fixed support 26 in the horizontal leg 22 of the elbow and also through a gland 27 in a closure plate 28 at the outer end of the burner. The outer end ofthe rod 25 is connected with an operating gear of any suitable construction. As here shown, the outer end of the rod has screw threads that are engaged by a nut (not shown) within an operating gear 29 of a type well known for operating gate valves, there being a handwheel 30 for operating the gear to propel rod 25 axially in one direction or the other in addition to a motor 30a customary in valve operating mechanisms of this type.

By the use of an axially movable telescopic intermediate section to provide the connection in the gas duct between the nose portion 5 and the after portion 22 of the burner, the burner construction is materially simplified and it becomes possible to use a disk valve, either water-cooled or of heat-resistant alloy, in place of the much more intricate arrangement heretofore necessary, and without any requirement for pits below the burner or other more expensive expedients proposed for disconnecting the burner from the stove when the stove is on the air heating cycle. The arrangement lends itself to a simple and quick automatic stove changing control since with motordriven valve operations the hot blast disk valve and the movable duct section need only by operated in controlled sequence from an automatic controller, as will be readily understood by those skilled in the art, such systems being known and forming no part of this invention.

The gas line is provided with the usual butterfly control valve, schematically indicated at 31, and there would ordinarily be provided a disk valve at a convenient place in the gas line, but which need not be of the double disk vented type now generally required, and no other valve is required in the air line. The burner itself, being close coupled to the burner nose, does not project horizontally very far from the base of the stove, and having the air enter the burner from the side and the gas from the top also contributes to the compactness of the burner. The elbow in the gas duct has as its rear wall the rear closure plate 28, so that there can he an extension 32 on the closure plate for an explosion and clean-out door 33. This door, as is usual, is biased to remain closed until an abnormal pressure is built up inside the burner when it will open to relieve such pressure. There is a clean-out 34 for the air duct at the bottom near the outer end.

While I have shown one specific embodiment of my invention, it will be understood that the parts may be constructed in various ways within the contemplation of my invention and under the scope of the following claims.

I claim:

'1. A gas burner for blast furnace stoves having a forward end from which air and gas are discharged when the burner is operating and an outer after portion, said burner having an outer air duct and a concentric axially-extending inner gas duct, the air duct having a forward section and an aligned after section, a gate valve body connecting the confronting ends of the two sections, a gate valve in the body movable in the body in a plane transversely across said air duct for closing the same against the reverse fiow of gases through the burner when the burner is out of operation and movable to a position clear of the duct passages when the burner is operating, said gas duct having three axially-aligned sections comprising a relatively fixed forward section forwardly of the path of movement of the valve gate, a relatively fixed after section rearwardly of the path of movement of the valve gate, and an intermediate section telescoping one of the fixed sections and movable in an axial direction across the path of movement of the valve gate into sealing engagement with the other fixed section when the valve gate is open to provide a continuous gas duct and movable to a position entirely to one side of the path of travel ofi the valve gate when the valve gate is to be moved to closed position, means outside the burner structure engaging said movable intermediate section for effecting movement thereof, and means fixedly joined to the after portion of the burner for supplying air and gas to the air duct and the gas duct respectively.

2. A gas burner for blast furnace stoves having a forward end from which air and gas are discharged when the burner is operating and an outer after portion, said burner having an outer air duct and a concentric axially-extending inner gas duct, the air duct having a forward section and an aligned after section, a gate valve body connecting the con-fronting ends of the two sections, a gate valve in the body movable in the body in a plane transversely across said air duct for closing the same against the reverse flow of gases through the burner when the burner is out of operation and movable to a position clear of the duct passages when the burner is operating, said gas duct having three axially-aligned sections comprising a relatively fixed forward section forwardly of the path of movement of the valve gate, a relatively fixed after section rearwardly of the path of movement of the valve gate, and an intermediate section telescopically engaging the after fixed section and movable in a direction axially of the body across the path of movement of the valve gate into sealing engagement with the rear end of the fixed forward section when the valve gate is open to provide a continuous gas duct and movable to a position entirely to one side of the path of travel of the valve gate when the valve gate is to be moved to closed position, an operating rod extending axially of the ducts attached to the intermediate section of the gas duct and having an outer end portion outside the burner for effecting movement of the intermediate section.

3. A burner for blast furnace stoves as defined in claim 2 in which the air duct has a closure plate at its outer end and the said intermediate section of the gas duct telescopes over the after section, the intermediate section having a spider therein, the operating means for moving the intermediate section comprising a rod attached to the spider and extending axially through the gas duct and end plate and sealed against the admission of air to the gas duct and having its other end accessible at the outer end of the burner.

4. A burner for blast furnace stoves as defined in claim 3 in which the after portion of the gas duct has a support therein for slidably supporting the rod.

5. A burner for blast furnace stoves as defined in claim 2 in which there is a closure plate over the air duct at the outer end of the burner, an air supply pipe enters the outer end of the air duct at right angles to the axis of the duct at one side thereof with a blower at the end of the air supply pipe, the after end of the gas duct comprising an elbow having a horizontal leg with which the intermediate section is telescopically engaged and a vertical leg passing vertically through the air duct and connected to a vertical gas supply main.

6. A burner for blast furnace stoves as defined in claim 2 in which there is a closure plate over the air duct and the outer end of the burner, an air supply pipe enters the outer end of the air duct at right angles to the axis of the duct at one side thereof with a blower at the end of the air supply pipe, the after end of the gas duct comprising an elbow having a horizontal leg with which the intermediate section is telescopically engaged and a vertical leg passing vertically through the air duct and connected to a vertical gas supply main, the blower having an air inlet, a vertical air pipe extending upwardly from the inlet for a distance of several feet, and an orifice plate in the vertical air pipe remote from the blower.

7. A burner for blast furnace stoves as defined in claim 2 in which there is a closure plate over the air duct at the outer end of the burner, an air supply pipe enters the outer end of the air duct at right angles to the axis of the duct at one side thereof with a blower at the end of the air supply pipe, the after end of the gas duct comprising an elbow having a horizontal leg with which the intermediate section is telescopically engaged and a vertical leg passing vertically through the air duct and connected to a vertical gas supply main, the closure plate for the air duct also forming a wall of said elbow, an explosion relief passage extending from the elbow through the closure plate to the outer end of the burner, and an explosion door on said passage.

References Cited in the file of this patent UNITED STATES PATENTS 967,416 McGarvey Aug. 16, 1910 1,563,605 iWillcox et al Dec. 1, 1925 1,976,208 Agthe et al Oct. 9, 1934 2,109,042 Bennett et al Feb. 22, 1938 2,269,699 Stoecker et a1. Jan. 13, 1942 2,529,768 Guy Nov. 14, 1958 FOREIGN PATENTS 216,829 Germany Dec. 4, 1909 

1. A GAS BURNER FOR BLAST FURNACE STOVES HAVING A FORWARD END FROM WHICH AIR AND GAS ARE DISCHARGED WHEN THE BURNER IS OPERATING AND AN OUTER AFTER PORTION, SAID BURNER HAVING AN OUTER AIR DUCT AND A CONCENTRIC AXIALLY-EXTENDING INNER GAS DUCT, THE AIR DUCT HAVING A FORWARD SECTION AND AN ALIGNED AFTER SECTION, A GATE VALVE BODY CONNECTING THE CONFRONTING ENDS OF THE TWO SECTIONS, A GATE VALVE IN THE BODY MOVABLE IN THE BODY IN A PLANE TRANSVERSELY ACROSS SAID AIR DUCT FOR CLOSING THE SAME AGAINST THE REVERSE FLOW OF GASES THROUGH THE BURNER WHEN THE BURNER IS OUT OF OPERATION AND MOVABLE TO A POSITION CLEAR OF THE DUCT PASSAGES WHEN THE BURNER IS OPERATING, SAID GAS DUCT HAVING THREE AXIALLY-ALIGNED SECTIONS COMPRISING A RELATIVELY FIXED FORWARD SECTION FORWARDLY OF THE PATH OF MOVEMENT OF THE VALVE GATE, A RELATIVELY FIXED AFTER SECTION REARWARDLY OF THE PATH OF MOVEMENT OF THE VALVE GATE, AND AN INTERMEDIATE SECTION TELESCOPING ONE OF THE FIXED SECTIONS AND MOVABLE IN AN AXIAL DIRECTION ACROSS THE PATH OF MOVEMENT OF THE VALVE GATE INTO SEALING ENGAGEMENT WITH THE OTHER FIXED SECTION WHEN THE VALVE GATE IS OPEN TO PROVIDE A CONTINUOUS GAS DUCT AND MOVABLE TO A POSITION ENTIRELY TO ONE SIDE OF THE PATH OF TRAVEL OF THE VALVE GATE WHEN THE VALVE GATE IS TO BE MOVED TO CLOSED POSITION, MEANS OUTSIDE THE BURNER STRUCTURE ENGAGING SAID MOVABLE INTERMEDIATE SECTION FOR EFFECTING MOVEMENT THEREOF, AND MEANS FIXEDLY JOINED TO THE AFTER PORTION OF THE BURNER FOR SUPPLYING AIR AND GAS TO THE AIR DUCT AND THE GAS DUCT RESPECTIVELY. 